1. Field of the Invention
The present invention relates to a scattered-ray grid, particularly for a medical X-ray device, of the type having a carrier with absorption elements, particularly in the form of lead elements, which are arranged in spaced rows, as well as to a method for determining the position of the absorption elements in a scattered-ray grid.
2. Description of the Prior Art
In radiographic technology, particularly medical diagnostics, scattered-ray grids are frequently utilized to attenuate the scattered radiation which is always present with the primary radiation. The grids that are currently used most are composed of a sequence of line-like radiation absorption elements in the form of lead lamellae, which, alternately, are coated with lamellae made of a base material. X-rays that are incident in the plane of the lamellae are only insignificantly attenuated by the base material. By contrast, the lead lamellae highly absorb radiation that is obliquely incident. Since such lead lamellae generate unavoidable lines on the radiograph and since the number of lines per centimeter is limited due to manufacturing reasons, it has been suggested to use pins made of lead or another absorption material arranged in rows, the pins being spaced apart, instead of using lead lamellae in a silicon base material. Such scattered-ray grids are known from the German OS 197 26 846 and OS 197 29 596, for example.
German OS 197 26 846 describes a configuration concerning the arrangement of the pins (and thus of the rows), wherein the rows extend to the center of the grid in a spoke-like manner. In this arrangement, many rows start at the same radius. The density of the absorption elements (seen in the radial direction) considerably varies as a result and grey tone discontinuities also occur, and the row spaces (seen in the tangential direction) significantly vary as well. This has a disadvantageous effect on the entire absorption behavior of the grid and therefore on the image quality.